Configure socket.io with node express generator - node.js

Question

I'm working on my first node project, I basically followed the thinkster post to get me started. I've managed to build a simple app and now I'm trying to configure socket.io.
The socket.io initialization code and event handlers are not hard to understand, what is really confusing me is how should I organize that code between the bin/www and the app.js files. Both files were generated automatically by express. bin/www depends on the app.js module, the first initiates the server variable which is needed to start up the socket module, so that means I should put all the 'socket.io' code in the bin/www file?
I don't think I should be touching that file though, I would be more comfortable putting that code into app.js or even inside a dedicated file. I think I need to pass the server object reference between modules, but I'm not sure how to do that.
This is the content of the bin/www file:
#!/usr/bin/env node
/**
* Module dependencies.
*/
var app = require('../app');
var debug = require('debug')('oculus:server');
var http = require('http');
/**
* Get port from environment and store in Express.
*/
var port = normalizePort(process.env.PORT || '3000');
app.set('port', port);
/**
* Create HTTP server.
*/
var server = http.createServer(app);
/**
* Listen on provided port, on all network interfaces.
*/
server.listen(port);
server.on('error', onError);
server.on('listening', onListening);
/**
* Normalize a port into a number, string, or false.
*/
function normalizePort(val) {
var port = parseInt(val, 10);
if (isNaN(port)) {
// named pipe
return val;
}
if (port >= 0) {
// port number
return port;
}
return false;
}
/**
* Event listener for HTTP server "error" event.
*/
function onError(error) {
if (error.syscall !== 'listen') {
throw error;
}
var bind = typeof port === 'string' ? 'Pipe ' + port : 'Port ' + port
// handle specific listen errors with friendly messages
switch (error.code) {
case 'EACCES':
console.error(bind + ' requires elevated privileges');
process.exit(1);
break;
case 'EADDRINUSE':
console.error(bind + ' is already in use');
process.exit(1);
break;
default:
throw error;
}
}
/**
* Event listener for HTTP server "listening" event.
*/
function onListening() {
var addr = server.address();
var bind = typeof addr === 'string' ? 'pipe ' + addr : 'port ' + addr.port;
debug('Listening on ' + bind);
}
And this the content of the app.js file:
var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var mongoose = require('mongoose');
// Mongoose
require('./models/Aplicacoes');
mongoose.connect('mongodb://localhost/oculus');
var routes = require('./routes/index');
var users = require('./routes/users');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
extended: false
}));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', routes);
app.use('/users', users);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
var err = new Error('Not Found');
err.status = 404;
next(err);
});
// error handlers
// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: err
});
});
}
// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
/**
* Some business code here
*/
....
module.exports = app;

Answer 1

First, let me tell you, what you're trying to do is kinda right. Not to mess with the bin/www would be fine.
But remember express generator is just that. A generator for you to build upon. You generate, and the apply your own modifications.
My choice would be to:
copy bin/www to a new bin/wwwio,
Update the bin/wwwio script to attach socket.io to the created http server.
Update bin/wwwio to require() a new file ../io.js that handles all my socket.io events.
Modifiy package.json to run node ./bin/wwwio on npm start instead of bin/www
You can also look at the answers on this other question about the some topic:
Using socket.io in Express 4 and express-generator's /bin/www
You'll find several approaches to achieving modularity with little touching on the bin/www script.

Answer 2

Try following these simple steps
Install Socket.io with the following command:
npm install --save socket.io
Add the following to app.js:
var sockIO = require('socket.io')(); app.sockIO = sockIO;
In bin/www,
after var server = http.createServer(app), add the following:
var sockIO = app.sockIO; sockIO.listen(server);
To test functionality, in app.js, you can add the line:
sockIO.on('connection', function(socket){ console.log('A client connection occurred!'); });
Now in layout.hbs add the following snippet before the body closing tag < /body >:
<script src="/socket.io/socket.io.js"></script> <script> var socket = io(); </script>
Further, I have created the GIT REPOSITORY for the complete working project of chat with Sockets express generator.
https://github.com/Mohsin05/Sockets-Express-Generator
I hope it will help everyone. ;)